Am pretty fortunate that am home most the time so he not need be left much and on whole someone else be home but will be odd time need to leave him or even put in his crate when need leave the room
have been feeding him in it and he sometimes sleeps in there in day and is in their at night and is pretty good bar needing toilet in night
but if you put him in there in day and shut door he crys and barks a lot and thats with me just being in house not sure how be if out .aware he is only a baby at 9 weeks but not sure how or when should start
But rather teach him now than end up having to out him and do it if have dash out ( ds4 has sn and sometimes need make a quick dash to school to collect him if poorly )
He's still very little, it might just take some perseverance. I expect you've done all the nice association things, putting a blanket in with your smell on, treats, toys, chews etc, have you tried building it up gradually? Shutting the door for a few seconds and giving him a reward?